Accumulator testing device



April 6, 1954 F. ALTENBACH 2,674,718

' ACCUMULATOR TESTING DEVICE Filed Jan. 5, 1951 3 Sheets-Sheet 1 ANCois ALtnv bawh "wh r.

A t Y'NLY April 6, 1954 Filed Jan. 5, 1951 F. ALTENBACH ACCUMULATO R TESTING DEVICE 3 Sheets-Sheet 2 April 6, 1954 F. ALTENBACH 2,674,718

- ACCUMULATOR TESTING DEVICE Filed Jan. 5, 1951 s Sheets-Shee. s

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Patented Apr. 6, 1954 ACCUMULATOR TESTING DEVICE Francois Altenbach, Asnieres, France Application January 5, 1951, Serial No. 204,598

4 Claims. 1

My invention has for its object an improved apparatus adapted to test accumulator batteries which apparatus comprises a pair of legs conductively connected with a voltmeter and characterized thereby that said pair of legs are addi-- tionally connected with an ammeter through a variable resistor; by means of such improved apparatus it is possible to check the battery element concerned for its voltage drop in either the no-current working condition or while the accu mulator is feeding back any desired and controlled amount of current.

Preferably, the voltmeter is attached to the top end of the handle of the apparatus and coaxial therewith while the ammeter is displaced laterally and the variable resistor is arranged axially between the pair of legs together with the resistance control means.

Two embodiments of the device according to my invention are illustrated merely for the purpose of exemplification in the drawings appended hereto, in which:

Figure 1 is a longitudinal section of a first embodiment taken on lines AA in Figs. 4 and 5.

Figures 2 and 3 are enlarged sectional and top views respectively, of details of the upper holding disc of the resistor as shown in Fig. 1.

Figure 4 is a side elevational view. Figure 5 is a top view.

Figure 6 is a longitudinal sectional view of secure conductive metal strips 26, 21 connected;

by cables 28, 29 extending through the handle I to a voltmeter I secured to the top end of said handle.

Retained between the legs 2, 3 of the fork by means of brackets 30, 32 is a variable resistor-.1." composed of a pair of gunmetal discs 11, I8 interleaved concentrically with a plurality of discs I made of a resistive material, e. g. carbon.

The bracket 30 is insulated from fork 2 by an insulating washer 3 I. J

Projecting centrally through the discs is a stud 33 screwed with its threaded lower end in a bottom disc I8 which is insulated with respect to the discs I9 and to the movable disc I! by a sleeve 34. Said stud is rigid with a manually Secured to the lowerrotatable collar or control knob 9 made of an insulating material.

Guided in the movable disc I1 and arranged around the stud 33 are a plurality of pushes 35 illustrated in more detailed manner in Figs. 2 and 3. Said pushes are made of an insulating and heat-resisting material and loaded by springs 36.

The disc I8 and the movable disc I! are provided with a plurality of stiffening and heatdissipating ribs 31, 38.

Secured to the leg 2 adjacent to the bend of the same is a thimble made of a conductive material and connected through a cable 40 and a thimble 4| with the ammeter 42.

The shunt circuit of the ammeter 42 ends at the thimble 43 which is connected with the movable disc I! through the cable 44 and the thimble 45.

Visible in Figs. 4 and 5 are the two meters, via: a central-zero sensitive 3-volt capacity voltmeter I0 and a central-zero large-capacity ammeter provided with a shunt circuit.

The operation is as follows:

The handle I of the apparatus is held by the operator with his left hand, after which he turns the knob or collar 9 completely to the left in order to completely out out the resistor due to the upward lifting action of the pushes 35 and the springs 36.

If in the no-current condition the voltmeter reads less than 1.8 volt it is of no use to worry about the current since the battery tested is either unloaded or out of condition.

If in said no-current condition the voltmeter reads 2 volts or more the operator turns the knob, whereby the resistor is switched in and current flows from leg 3 through the screws 32, the fixed disc I8, the variable resistors I9, the movable disc H, the thimble 45, the cable 44, the thimble 43, the ammeter 42, the thimble 4|, the cable 40 and the thimble 39 to the leg 2.

The circuit is thus closed through the terminal of the storage battery to be checked.

It will be assumed that a '75 ampere-hour storage battery is to be checked. The knob 9 is rotated towards the right so as to increase the pressure exerted upon the discs I9 by the discs I1, I8 and thereby to decrease the resistance through said discs l9 until the output is equal to twice the capacity of the cell to be checked, that is, 2=150 ampere-hours in the case under consideration.

In the modification illustrated in Figs. 6 and 7 the handle I is made of plastic material solid with the casing of the voltmeter l and secured to the top portion of the body of the apparatus to which the legs 2, 3 are secured with the aid of screws 4 and 5.

Secured by means of a pair of lugs between said legs assembled to a fork is the variable resistor consisting of a pair of metal discs [1, it which are interleaved with discs l9 made of a resistive material, e. g. electro-carbon.

The leg 2 is insulated from the lug by which the disk [8 is retained.

The central stud 23 is provided with a threaded portion engaged in a hole tapped in disc It; said stud is keyed on the knob 9 and insulated from" the discs I! and I! by the insulating sleeve 22; it is connected for sliding motion with the insulating and heat-resisting washer 2| by a ring 20 keyed on said stud.

Projecting through the hub of the knob 9 made of plastic material is a metal sleeve 8; a screw I is provided to exert a greater or less pressure upon a wire braid coiled to a collector 1.

The shunt circuit l3 of the amineter is connected at its one end to said collector 1 through a member I2 and at its opposite end through member ll, screw 4, and the metal sleeve Hi to the leg 2.

Here again, screws 4 and 5 connect the legs 2, 3 with the voltmeter It.

The operation is as already described.

What I claim is:

l. A portable apparatus for testing the condition of a storage battery by causing said apparatus to bear on the terminals of the battery to measure the voltage without output, and to simultaneously measure the voltage and the output, said apparatus comprising a handle of insulating material, a pair of pointed prongs mounted on said handle and adapted to be pressed against the terminals of the battery to be tested, a voltmeter and an ammete'r both of the central zero type mounted on said handle, a variable resistor mounted between said prongs said variable resistor comprising electrically resistive discs stacked coaxially about a central shaft and between an upper upwardly displaeeable metal disc and a bottom disc at the lower end of said central shaft, a direct electrical connection between said pointed prongs and said voltmeter, an electrical connection between said pointed prongs and said ammeter through said variable resistor, and a manually rotatable insulating collar coaxial with the center shaft and integral with said upper metal disc to connect or disconnect said upper disc to said electrically resistive discs by the rotation of said collar and metal disc to displace the metal disc towards or upwardly away from the resistive discs, thereby manually disconnecting said variable resistor when it is desired to read the voltage without output on said voltmeter and setting said resistor to the value adapted to cause the desired instantaneous current output to be read. on said ammeter to flow through said resistor when it is desired to read on said voltmeter the battery voltage corresponding to said instantaneous output.

2. A portable apparatus for checking the condition of a storage battery by causing said apparatus to bear on the terminals of the battery to measure the voltage without output, and to simultaneously measure the voltage and the output, said apparatus comprising a handle of insulating material, a pair of pointed prongs mounted on said handle and adapted to be pressed against the terminals of the battery to be tested,

a voltmeter and an ammeter mounted on said handle and each provided with a pair of terminals, electrical connections between each of said prongs and the pair of terminals of said voltmeter, a metal disc rigidly mounted between said prongs, electrically resistive discs stacked coaxially on said metal disc, another metal disc coaxially and slida'bly mounted above said resistive discs, both said metal discs being provided with cooling fins and all said discs being so mounted as to be freely exposed to the surrounding atmosphere, a manually rotatable insulating collar coaxial with and immediately above said metal disc and above said resistive discs to connect or disconnect said metal discs from said resistive discs by rotating said collar and metal disc to displace the metal disc upwardly away from the resistive discs and thus adapted for either moving the other of said metal discs away from said electrically resistive discs or clamping said other metal disc and said electrically resistive discs against said first metal disc, an electrical connection from one terminal of said ammeter to one of said prongs, an electrical connection from said lastmentioned prong to one of said metal discs and an electrical connection from said other metal disc to the other terminal'of said ammeter.

3. A portable apparatus for controlling the condition of a storage battery by causing said apparatus to bear on the terminals of the battery to measure the voltage and the output, said apparatus comprising a handle of insulating material, a pair of pointed prongs mounted on said handle and adapted to be pressed against the terminals of the battery to be tested, a voltmeter and an ammeter mounted on said handle and each provided with a pair of terminals, electrical connections from said prongs to the pair of terminals of said voltmeter respectively, a metal disc formed with an axial internally-threaded hole and rigidly mounted between said prongs, a shaft having a screw-threaded shank, engaged in said internally threaded hole of said metal disc, an insulating washer axially rigid with said shaft, said metal disc being formed with a central concavity adapted to receive said washer, an insulating tubular element surrounding said shaft, electrically resistive discs formed with an axial hole, surrounding in turn said insulating tubular element and bearing on said insulating washer, said discs having a diameter greater than said concavity, another metal disc formed with an axial hole and surrounding said insulating tubular element and bearing on said electrically resistive discs, said shaft being formed with a head emerging above said insulating tubular element and said other metal disc, an adjusting hand-lever of insulating material secured on said shaft head, an electrical connection from one of said ammeter terminals to one of said prongs, an electrical connection from said lastmentioned prong to said first metal disc, and an electrical connection from said other metal disc to the other ammeter terminal.

4. A portable apparatus for testing the condition of a storage battery by causing said apparatus to bear on the terminals of the battery to measure the voltage without output, to simultaneously measure the voltage and the output, said apparatus comprising a handle of insulating material, a pair of pointed prongs mounted on said handle and adapted to be pressed against the terminals of the battery to be tested, a voltmeter and an ammeter mounted on said handle and each provided with a pair of terminals, electrical connections from said pair of prongs to said terminals of said voltmeter, respectively, a metal disc formed with an axial internally-threaded; hole and rigidly mounted between said prongs, a shaft formed with a screw-threaded shank engaged in said internally-threaded hole of said metal disc, an insulating washer axially rigid with said shaft, said metal disc being formed with a central concavity adapted to receive said insulating washer, an insulating tubular element surrounding said shaft, electrically resistive discs each formed with an axial hole and surrounding said insulating tubular element while resting on said insulating washer, said discs having a greater diameter than said concavity, another disc formed with an axial hole surrounding said insulating tubular element and resting on said electrically resistive discs, said shafts being formed with a head emerging above said insulating tubular element and said other metal disc, an adjusting hand-lever of insulating material secured on said shaft head, a metal socket passing coaxially through said adjusting handlever, fast therewith and having an upper end ring and the other terminal of said ammeter.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,772,217 Heyer Aug. 5, 1930 1,882,581 Haskins Oct. 11, 1932 1,974,440 Allen Sept. 25, 1934 2,066,058 Simpson Dec. 29, 1936 FOREIGN PATENTS Number Country Date 285,671 Italy May 19, 1931 748,410 France July 4, 1933 

